Rigorous trainer selection
Each trainer is validated on three criteria: hands-on field expertise, proven pedagogy and alignment with your industry.
- Triple validation: technical, pedagogical, sectoral.
- Minimum rating 4.8/5 over the last 12 sessions.
1 seat held for the next session
30:00Held for another
Request a call back and an advisor reaches you within 24 business hours, Monday to Saturday.
Trusted by — schools, companies and industrial groups
Every program built with a dedicated engineer
Learning objectives
- Integrate Web3.js for secure multi-chain provider connections
- Develop advanced interactions with complex smart contracts
- Manage events and real-time subscriptions for scalable dApps
- Optimize gas and performance in production environments
- Implement advanced security against reentrancy and front-running attacks
- Deploy and monitor full-stack dApps with Web3.js
- Create automated scripts for testing and CI/CD deployments
Our social commitment
A school kit donated to a child for every training booked
To fight inequalities in access to education, Learni donates a complete school kit to a child in need for every training booked. You build your skills, a child heads back to school.
- Backpack, notebooks and essential supplies
- Distributed through our partner charities
- Included, at no extra cost to you
The Learni story
Founded by engineers and learning experts, Learni's mission is to make high-impact tech training accessible to teams everywhere. We work remotely with organizations across the US and Canada, in your time zone, to help teams upskill fast.
Don't let this gap widen
Why this program matters
Without expert Web3.js mastery, 70% of dApps fail security audits, exposing them to hacks that cost an average of 3M€ per incident, such as Ronin (625M$ stolen).
You lose 40% of gas unnecessarily on poorly optimized transactions, miss 25% performance in faulty subscriptions, and forgo DeFi/NFT opportunities that generate x10 ROI.
Your competitors deploy scalable solutions on L2 while your prototypes crash in prod, and gas fees explode +200% without batching.
Invest 28h or risk obsolescence: 80% of junior devs stagnate without upskilling Web3.js, avoid project delays and client losses.
Program
Module 1Advanced Web3.js Fundamentals: Providers and Utils (tools, connections, initial scripts)
Dive into the installation and configuration of Web3.js 4.x, connect to various providers like Infura or Alchemy through practical exercises, handle accounts, balances, and batched transactions on testnets, create your first utility scripts for signing and broadcasting, test live on Sepolia to validate robustness and scalability, leave with ready-to-use templates that boost your immediate productivity.
Module 2Smart Contract Interactions: Calls, Transactions, ABI (methods, encoding, multisig)
Master view/pure calls and state-changing mutations with dynamic ABIs, encode/decode complex parameters via exercises on ERC-721/1155 contracts, manage multisig and batch transactions for gas savings, simulate interactions on mainnet forks with Hardhat, develop a functional decentralized wallet, integrate log parsing for advanced debugging, experience the thrill of deploying your own interactive contracts in real-time.
Module 3Events and Subscriptions: Listening, Filters, IPFS (WebSockets, optimized polling)
Set up WebSocket subscriptions for real-time events on Polygon and Optimism, filter logs with advanced topics and bloom filters, integrate IPFS for decentralized metadata via NFT dApp exercises, optimize hybrid polling for maximum reliability, manage automatic reconnections and backoff strategies, build a live transaction monitoring dashboard, feel the power of a reactive dApp that captures every blockchain event instantly.
Module 4Production dApps: Security, Optimization, Monitoring (audits, MEV, CI/CD deliverables)
Secure against reentrancy and sandwich attacks with Web3.js guards, profile gas via batch estimations and optimize loops, integrate TheGraph for indexing queries, deploy full-stack dApps with React/Vue through practical workshops, audit your code with integrated Slither, set up CI/CD GitHub Actions for automated tests, finalize a capstone project deployed on Vercel/IPFS, leave certified with a professional portfolio that impresses recruiters.
Evaluation method
- Daily technical quizzes, peer code reviews, final deployed dApp project, Qualiopi certification.
Learning method
- 100% hands-on with real Ethereum cases, live coding, individualized feedback.
Methods, materials and delivery
The Training Web3.js - Develop Advanced Blockchain dApps program is delivered onsite or remote (blended-learning, virtual classroom, remote presence). At Learni, an industry-certified training organization, every program is built to maximize skills acquisition regardless of the chosen format.
The trainer alternates between demonstrative, interrogative and active methods (through hands-on labs and/or scenarios). This pedagogical approach guarantees concrete learning that's immediately applicable at work.
Equipment required
For the smooth delivery of the Training Web3.js - Develop Advanced Blockchain dApps program, the following equipment is required:
- Mac or PC computers, high-speed fiber internet, whiteboard or flipchart, projector or interactive touch screen (for remote sessions)
- Training environments installed on workstations or accessible online
- Course materials, hands-on exercises and complementary resources
- Post-training access to materials and educational resources
For intra-company training on a site outside Learni, the client commits to providing all required teaching materials (computers, internet, etc.) for the smooth delivery of the program in line with the prerequisites in the communicated program.
* contact us for remote delivery feasibility** ratio varies depending on the program
Skills assessment methods
Assessment of skills acquired during the Training Web3.js - Develop Advanced Blockchain dApps program is performed through:
- During training: case studies, hands-on labs and professional scenarios
- End of training: self-assessment questionnaire and skills evaluation by the trainer
- After training: completion certificate detailing acquired skills
Program accessibility
Learni is committed to making its programs accessible. All our programs are accessible to people with disabilities. Our teams are available to adapt the pedagogical methods to your specific needs. Please contact us for any adjustment request.
Enrollment terms and lead times
Registration is possible up to 48 business hours before the start of training. All our programs are built for corporate L&D budgets and delivered onsite or remotely.
Our method
Training quality, guaranteed at every step
Before, during, after: we frame the brief, introduce the trainer, tailor the content and measure impact. You stay in control from kickoff to wrap-up.
You meet the trainer beforehand
30-minute video call between you and the selected trainer to validate the fit, adjust content and clear any final doubts.
- Live briefing on goals and team context.
- Veto right — we swap the trainer for free if needed.
Content tailored to your context
No recycled slides. The syllabus is reworked from your real cases: tools, constraints, vocabulary, ongoing projects.
- Hands-on cases drawn from your stack and projects.
- Program co-written then validated by your team.
Continuous quality follow-up
Live evaluations, 30/90/180-day check-ins and a consolidation plan. If the impact misses the mark, we rework it.
- NPS, knowledge quizzes and skills self-assessment.
- Satisfaction guarantee: fully satisfied or free rework.
A simple promise: you don't pay to discover the trainer on day one. Everything is validated upfront, by you.
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FAQ
Frequently asked questions
Which tools are used in Web3.js training?+
Hands-on work runs on tools, connections, initial scripts, methods, encoding and multisig. Those tools come from the Web3.js program itself, delivered on site over 4 days, so participants practise on the stack they will use at work.
What can participants do after Web3.js training?+
They can integrate Web3.js for secure multi-chain provider connections, develop advanced interactions with complex smart contracts and manage events and real-time subscriptions for scalable dApps. Those are the stated objectives of the Web3.js program at Expert level, checked by the end-of-session assessment.
What does the Web3.js program cover, day by day?+
Day 1: Advanced Web3.js Fundamentals: Providers and Utils (tools, connections, initial scripts). Day 2: Smart Contract Interactions: Calls, Transactions, ABI (methods, encoding, multisig). Day 3: Events and Subscriptions: Listening, Filters, IPFS (WebSockets, optimized polling). Day 4: Production dApps: Security, Optimization, Monitoring (audits, MEV, CI/CD deliverables). The Web3.js program runs over 4 days, delivered on site.
How is Web3.js training assessed?+
Assessment relies on daily technical quizzes, peer code reviews, final deployed dApp project, Qualiopi certification. Learni issues a completion certificate together with the individual assessment report at the end of the Web3.js program, which an L&D team can file as evidence.
How much does Web3.js training cost per participant?+
$4,620 (USD) per participant. A detailed quote is sent within one business day, and team pricing applies from the second participant.
How long does Web3.js training take?+
4 days, available live online (US time zones) or on-site at your offices. Half-day tracks spread over several weeks are possible so the team stays operational.
Who pays for Web3.js training?+
Most US teams pay directly through their company L&D or training budget. Learni invoices in US dollars and accepts bank transfer (ACH/wire) or card, with volume pricing for teams. A purchase order is welcome.
What do participants need to know before Web3.js training?+
Advanced proficiency in JavaScript ES6+, experience with Solidity and Ethereum, knowledge of blockchain APIs such as Ethers.js.
Is a certificate issued after Web3.js training?+
Yes. A Learni completion certificate is issued, along with the individual evaluation report. Learni is a certified training provider and prepares for third-party certifications, but does not award them itself.
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